DVM Clinical Pathology and Diagnostics 2 — Questions and Answers
Question 1: A dog presents with a PCV of 18% and marked spherocytosis on blood smear. Which Coombs test result would confirm immune-mediated hemolytic anemia?
- Negative direct Coombs
- Positive direct Coombs (Correct answer)
- Negative indirect Coombs
- Positive indirect Coombs only
Correct answer: Positive direct Coombs
A positive direct Coombs test detects antibodies or complement bound to the surface of red blood cells, confirming IMHA.
Question 2: A cat's urinalysis shows a USG of 1.008 with concurrent azotemia. How should this finding be interpreted?
- Prerenal azotemia with adequate concentrating ability
- Postrenal azotemia
- Renal azotemia with inadequate concentrating ability (Correct answer)
- Normal finding in cats
Correct answer: Renal azotemia with inadequate concentrating ability
A USG of 1.008 (isosthenuria) with azotemia indicates the kidneys cannot concentrate urine, pointing to primary renal disease.
Question 3: Which bone marrow finding is most consistent with a diagnosis of aplastic anemia in a dog?
- Hypercellular marrow with myeloid hyperplasia
- Hypocellular marrow with fat cell replacement (Correct answer)
- Increased megakaryocytes only
- Erythroid hyperplasia with left shift
Correct answer: Hypocellular marrow with fat cell replacement
Aplastic anemia is characterized by hypocellular marrow where hematopoietic cells are replaced by fat cells, causing pancytopenia.
Question 4: A horse has serum chemistry showing total bilirubin of 8 mg/dL with direct bilirubin of 0.4 mg/dL. What is the most likely cause?
- Hepatocellular disease
- Biliary obstruction
- Fasting hyperbilirubinemia (Correct answer)
- Hemolytic anemia
Correct answer: Fasting hyperbilirubinemia
Horses commonly develop fasting-induced hyperbilirubinemia due to decreased hepatic uptake of unconjugated bilirubin, with predominantly indirect fraction elevated.
Question 5: On cytology of a lymph node aspirate, you observe a monomorphic population of large lymphocytes with prominent nucleoli comprising >80% of cells. What is the most likely diagnosis?
- Reactive lymphoid hyperplasia
- Lymphoma (Correct answer)
- Suppurative lymphadenitis
- Granulomatous lymphadenitis
Correct answer: Lymphoma
A monomorphic population of large, atypical lymphocytes exceeding 80% of the cell population is highly indicative of lymphoma.
Question 6: A bovine blood sample shows a fibrinogen concentration of 900 mg/dL (reference 200–400 mg/dL). Which condition is most consistent with this finding?
- Disseminated intravascular coagulation
- Hepatic failure
- Acute inflammation or infection (Correct answer)
- Protein-losing nephropathy
Correct answer: Acute inflammation or infection
Fibrinogen is a major acute-phase protein in cattle, and markedly elevated concentrations indicate significant inflammation or infection.
Question 7: A dog's CBC reveals a leukocyte count of 32,000/µL with 85% neutrophils, 10% bands, and toxic changes including Döhle bodies. What does this pattern indicate?
- Physiologic leukocytosis
- Chronic steroid hepatopathy
- Severe bacterial infection with left shift (Correct answer)
- Leukemia
Correct answer: Severe bacterial infection with left shift
A marked leukocytosis with bands and toxic neutrophil changes (Döhle bodies, vacuolation) indicates a strong demand for neutrophils, typical of severe bacterial infection.
DVM Clinical Pathology and Diagnostics 2
A dog presents with a PCV of 18% and marked spherocytosis on blood smear.
Which Coombs test result would confirm immune-mediated hemolytic anemia?